SELECT On Tabe PRPS not working

HI Experts,

Below is my select query.

SELECT SINGLE PSPNR
               POSID
               ZSECOND_BU
               ZCORPGROUP
               USR01
               OBJNR
               ZDEPROJTYPE FROM PRPS INTO WA_PRPS
                WHERE PSPNR = <FS_OUTTAB>-PROJK.

Eventhough it is running with SY_SUBRC = 0. It is not fetching all the values in Select query. For example the values such ZSECOND_BU & ZCORPGROUP are coming as null. Any ideas why so? I have tried with some conversion exits as well.

BR.